Means for separating the spring fingers of feed chucks



N 21, 1950 A. J. DADDONA 2,530,569

MEANS FOR SEPARATING THE SPRING FINGERS 0F FEED cnucxs Filed Nov. 27, 1948 a 1 4.40? neg/5.

Fatented Nov. 21, 1950 MEANS FOR SEPARATING THE SPRING FINGERS OF FEED CHUCKS Anthony J. Daddona, Elmira, N. Y., assignor to Hardinge Brothers, Inc., Elmira, N. Y.

Application November 27, 1948, Serial No. 62,348

3 Claims. 3

This invention relates to improvements in feed chucks of the kind commonly used for advancing work in automatic screw machines or the like, and more particularly to feed chucks of the type in which removable work engaging pads are arranged at the ends of the spring fingers of the chuck.

One of the objects of this invention is to provide means of improved construction for facilitating the spreading apart of the spring fingers of a feed chuck for the purpose of inserting and removing the Work engaging pads. A further object is to provide spreading means of this type which may be used in connection with standard pads without requiring any changes in the pads themselves. Other objects and =advantages will be apparent from the following description of one embodiment of the invention and the novel features will be particularly pointed out hereinafter in connection with the appended claims This invention relates to improvements in feed chucks of the general type shown in the Daddona application for patent No. 684,390, filed July 17, 1946.

In the accompanying drawings:

Fig. 1 is a side elevation of a feed chuck embodying this invention and showing the same engaging the workpiece.

Fig. 2 is an end view thereof, taken on'line 22, Fig. 1.

Fig. 3 is a perspective view of a tool or implement for spreading or separating th spring fingers.

Fig. 4 is a fragmentary longitudinal central sectional elevation of the feed chuck, the section being taken on line 4-4, Fig. 2.

Fig. 5 is a fragmentary side elevation of the feed chuck showing the fingers thereof separated by means of the implement shown in Fig, 3.

Fig. 6 is a transverse section thereof, on line G-6, Fig. 5.

The improvements embodying this invention may be applied to any suitable or desired type of feed chuck, that shown for purposes of illustration including the usual tubular body portion 8 having one end thereof threaded as shown at 9 for attaching the feed chuck to a part of an automatic screw machine or other type of machine which moves the feed finger back and forth for feeding the work In. The feed chuck may be provider with any desired number of feed fingers H, these fingers being formed by means of longitudinal slots E2 cut into the feed chuck from one end thereof and terminating at a distance from the other end. These slots may be of any suitable type, those shown having enlarged portions l3 arranged at the inner ends of the slots l2. The feed chuck is preferably provided at the outer or free ends of the feed fingers l l with suitable work engaging pads it, one pad being provided for each spring finger, and the width of each pad being preferably coextensive with the width of the finger on which it is used. These pads l5 have their inner faces formed to engage the work It and the pads are formed so as to engage th spring fingers to hold the pads in place with relation to the fingers. Any suitable or desired means ma be employed for holding these pads on the spring fingers, and in the construction shown, each finger is provided with an aperture [6 near the end thereof and each pad is provided on the outer face thereof with a projection ll formed to extend into the aperture it. It will be noted that when th work is positioned in the feed chuck, the spring fingers will press the pads against the work with sufficient force to ensure the feeding of the work when the feed chuck is reciprocated, and this pressure of the pads against the work also serves to hold the projections H in the holes or apertures 56 in the spring fingers. When the work is removed from the feed chuck, the resiliency of the spring fingers causes the free ends of the spring fingers to move toward each other and will then press the adjacent edge portions IQ of the pads against each other. Pads and holding means of any other suit able or desired construction may be employed if desired.

In order to facilitate the removal of the pads from the spring fingers by separating the free ends of the fingers from each other, various tools or implements have heretofore been provided which extend into the slots l2 of the feed chuck and by means of which the outer ends of the spring fingers may be pried apart. Generally such tools or implements are applied to portions of feed chucks intermediate of the ends thereof, for the reason that the pads themselves interfere with the insertion of tools or implements into the outer ends of the slots to enable the spring fingers to be pried apart In accordance with this invention, however, the implement for spreading or separating the outer ends of the spring fingers is constructed to operate very near to the outer ends of the spring fingers, where the minimum amount of force is required to separate the fingers, this being particularly desirable when this invention is used in connection with large feed chucks in which a great deal of force is required to separate the outer ends of the spring fingers.

In accordance with this invention, enlargements 2B are provided in the slots 12 adjacent to the outer ends thereof, formed by cutting recesses in the Spring fingers adjacent to the ends thereof, two such recesses being shown at opposite edge. portions of. adiacentspring fingers and facing each other, but if desired; the enlargement may be formed by a single recess in only one of two adjacent edges of the spring fingers. These enlargements have parallel:edgesgextending parallel to the edges of the slots 12: andlare of sufiicient length to enable an implement to be inserted into the enlargement, and: the; enlargement is preferably so located with reference to the slot i2 that the enlargement doesv not extend to the open end of the slot 12, nor into the enlarged portion I3 of the slot, so that a portion of the narrow slot l2 extends beyond the enlargement 20 to the outer end of the feed chuck and to the enlarged portion I3. An implement with a fiat end portion may, consequently, beinserted into the enlargement 28 and turned through approximately 90 degrees so as to pry the spring fingers apart and the fact that the enlargement does not extend to the endof the feed.- chuck nor into the enlarged portion l3 would prevent the implement from slipping out of' the slot lengthwise thereof.

It is, however, also desirable to-provide means for preventing the instrument from-slipping out of the enlargement 2B laterally or radially of the feed chuck, and for this purpose, an implement may be provided as illustrated: particularly in Figs. 3, and 6. This implement may have a handle Zof any suitable form and may have an end portion thereof bent over and provided atits outer end with a key 25 which includes-two fiat sides, the key being of such size that it can read.- ily be inserted. into the enlargement: 20; with the fiat sides extending substantially. parallel to the length of the feed chuck. It willbenotedthat the key portion of the implement ispreferahly of approximately T-shap being provided. with notches 29 in the side thereof, thus forming; a head with lateral extensions 28.at the, endv of the key portion. The implement 2 's is preferably made of stock that is substantially circular: in cross section and the key may-be formedbyfirst cutting an annular groove adjacent to theend portion of the implement and. then milling or otherwise cutting the metal from opposit sides of the key portion, thus forming aflat neckterminating at its outer end in an. enlarged head. When the key. portion of. this implementis. in.- serted into the enlargement 28 ofthe slot 12;, the end 36 of the implement from which the key portion projects forms a shoulder which. acts as, a stop to limit the extent to which the key may be inserted into the enlargement. When the implement is turned through approximately a right angle into the position shownin-Figs; 5 and 6, the projections 28 forming the head of. the F- shaped key will be in positions to engage the inner surfaces of adjacent spring fingers H- so that removal of the key portion laterally of the feed chuck is absolutely prevented; This. therefore, makes it sa e to operate even ona large'size feed chuck by means of the implements shown, since it is impossible for the implement to nioveout of its finger spreading position and thus inad vertently to permit the fingers-to come together.

Since the-pads ordinarily fit snugly within the inner surfaces of the spring fingers, it'is necessary to provide some means for permitting the key portion of the implement to be completely inserted into the enlargement 20 of the slot, so that the head of the key will be within the interior of the feed chuck, and for this purpose, the interior surfaces of the spring fingers adjacent to the enlargements 20 are provided with recesses or undercut portions 3! at each: side: of the enlargements 20 of the slots l2. These recesses must be of sufiicient depth to permit the head of the T-shaped key to enter into the same. The key portionis made of such length that when the circular'stop portion or shoulder 30 engages the outer surface of the spring fingers, the inner edge'of the key; portion will not press against the pads l5; which would interfere with the ready removal. of; the. same and with the replacing of other pads between the ends of the spring fingers. These recesses may readil be formed in the spring fingers by means of circular grinding or cutting tools which-may be inserted.- into themterior of the feed chuck during their: cutting operations. Consequently, because ofs'these'recesses-3l in the. sprin fingers, the key: portions;of the implements canbe readily insertedintoxthe enlargements Elldnthe slots and theimplements then turned through about degrees to pry. the ends of the springfingersapart. Since the keys on the end of the implementswill belocatedentirely within therecesses or undercut .portionsifi of the spring fingers, they will notin any way interfere withv the removal: or replacement of the pads.

By means of the construction.- described, pads such as heretofore commonly. used: on feed chucks, may be used without change on.:. feed chucks constructed according. to. this invention.

It will be understood that.various.changes.-. in the details, materials, and. arrangementsof parts which havebeen herein described and; illustrated in order to explain the nature of the invention, may be madeby those skilled in the art:within the: principle and scope of the invention, as.ex:- pressed in the appended claims.

I claim as my invention:

1. An improved feed. chuck: with a passage theriethrnugha and. comprising a; plurality; of spring fingers all anchored at one endand'freeat their other. ends, thev free endsbeing'separated by slots running lengthwise from said. free ends, anda work engaging padiremov-ably fittingrthe inner face of'each free end of afinger: andtextending lengthwise along it for a substantialdisitance, each slot. havingan enlargement inwidth in the portion; past which the padsextendiand spaced from the frees-openend. of the slot bycan unenlarged portion, each of saidfingers ata side ofan. enlargement of. a .slot being underculi t'o form a spacebetween a. Spring fingerrand a pad, whereby whena key with a. fiat end is inserted in said enlargement and turned to spread'said fingers, a .fiange-on: the inserted free end; of the key may-turn inisaidspace to lie alon the-inner face of a. finger and prevent endwise removal of the key. from the slot while the fingers arespreadby that key.

2; A feed chuck having spring fingers extend ing lengthwise thereof and terminating atone endof said chuck and spacedfrom eachother by longitudinal slots, 2. work engaging pad removably connected with the end portion ofeach spring finger and removable from saidspring firrgers when the same areseparated, said.slots"hav-'- ingenlargements adjacent to the. outer ends thereof, the inner faces of saidspring fingers ad'- jacent to each enlargement having undercut recesses therein at the sides of said enlargements of said slots which form spaces between said pads and said spring fingers into which a head of a key may enter when the key is inserted in a radial direction into an enlargement to spread said spring fingers apart to prevent movement of the key laterally of said feed chuck.

3. The combination of a feed chuck having a plurality of spring fingers anchored at one end and free at their outer ends, said sprin fingers being separated from each other by slots extending lengthwise from said free ends, work engaging pads removably fitting the inner faces of the free end portions of said fingers, each slot having an enlargement in width in a portion past which the pads extend and spaced from the free open end of the slot by an unenlarged portion, said spring fingers at the enlarged portions of said slots being provided on their inner faces with recesses forming spaces between said spring fingers and said pads, whereby an implement for spreading apart said free ends of said spring fingers and including a shoulder and a T-shaped flat key formed on the end thereof and extending beyond said shoulder, may be inserted in a direction radial to said feed chuck into said enlargement of said slot with the flat faces thereof extending substantially parallel with said slot, said implement when turned through approximately 90 degrees causing said key portion to spread said fingers apart and causing the head of the T-shaped portion to enter into said recesses of adjacent fingers, said recesses of said enlargement confining said head of said key portion against movement both lengthwise of said slot and radially of said feed chuck.

ANTHONY J. DADDONA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,725,492 Tessky Aug. 20, 1929 1,937,236 Laughlin Nov. 28, 1933 2,069,775 Rich Feb. 9, 1937 

